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F. H. MAYOH.

LATHE BROACHING ATTACHMENT.

APPLICATION FILED APR.29. 19m.

1 ,3 1 9,482 .1. v Patented Oct. 21, 1919.

3 SHEETSSHEET l- V] 7 N55 5155 11V VE/V 1 016.

T m comma PLANOGRAPH 00., WASHINGTON, ma

F. H. MAYOH. [AIME BROACHING AITACHMENT. APPLICATION FILED APR- 29.19MB.

1,319,482. Patented Oct. 21,1919.

3 SHfETS-SHEET 2.

lV/TNESSES:

INVEN'T OR.

Tim COLUIIIIIA PLANounAPn c0., WASHINGTON, I). c.

F. H. MAYOH.

LATHE BROACHING ATTACHMENT;

APPLICATION FILED APR. 29. ms.

Patented Oct. .21, 1919.

3 SHEETS-SHE'ET 3.

Page 717. F f

WITNESSES: 11V VEN T OR.

FRANK H; Maren, 0F rAwTUoKET; BHonE IsLAiin;

LATHE BROACHING ATTACHMENT.

Specification of Letters Patent.

Patented Oct. 21 1919.

Application filed April 29, 1913; Serial 110.231544.

To all whom it may concern:

Be it known that I, FRANK I-I. lVIAYoI-I, a

' citizen of the United States, residing at Pawtucket, in the county of Providence and State of Ithode Island, have invented certain new and useful Improvements in Lathe Broaching Attachments; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to breaching attachments.

The object of the invention is to provide a novel and improved construction whereby a breach, such as has been on the market, and with which operators have become familiar may be pulled or drawn through work that is to be so operated on.

To these ends the invention consists of the features of construction and combinations of parts hereinafter described and referred to in the claims, the advantages of which will be apparent to those skilled in the art from the following detailed description of the breaching attachment in which the preferred form of the invention has been embodied.

In the drawings, which are shown on three sheets, Figure 1 is a front elevation on a reduced scale of an engine lathe with the breaching attachment in place, in its preferred form, the attachment upon which the invention is claimed being inclosed by the line with the section lines outside of it labeled attachment, Fig. 2 is a portion of a front elevation of a lathe with a breaching attachment in place in its preferred form for handling small breaches the principle of operation being the same whether the construction be as shown by Fig. 1 or Fig. 2. Fig. 8 is a front elevation of the breaching attachment that is shown in position on the engine lathe by Fig. 1 and Fig. 4 is an end View of the breaching attachment as shown in Fig. 3, except that some of the details of construction have been omitted to avoid confusion.

Fig. 5 represents the details of eonstruction for securing the breach to the holder. Figs. 6 and 7 represent an end view and a plan view respectively of the same. Fig. 8 and Fig. 9 represent one form of work holding plate and illustrate how a gear X would be held to the bushing E while the breach F is pulled through it. This bushing E is mounted in the right hand end of the attachment as indicated in Figs. 1, 2 and 3.

The breaching attachment as shown is held to a lathe or similar combination of revolving parts having so called forward and reverse motion and by rearrangement of the parts it might be adapted to a milling machine or similar arrangement of revolving parts. In future references the word lathe" is taken to indicate such combinations of revolving parts as mentioned above and machines to which adaption is evident to those skilled in the .art to which it pertains.

The means of operating the breaching attachment are contained. in the lathe except as will be noted in additional references, the bi sic functions necessary being to cause the machine to rotate in the usual manner with which operators are generally familiar.

The part A so indicated in all the views carries a nut B. This nut is internally threaded and is securely held so it will revolve with A. The red C is known. as the draw rod and is threaded with the same lead as the nut B. On the end of this draw rod (J, suitable units D are securely held in place, these being provided for suitably holding the breach and are similar to some new in use with which operators are generally familiar. Other parts to this attachment are the bushing E known as a work bushing and some form of breach F. These various units are held by a suitable bracket or brackets G to the lathe while A is held to the revolving part of the lathe at H in a suitable manner.

The work holding bushing E has mounted on it the gear X. This is to be breached by the breach F. The breach F is held to the unit D by the bushing Z. This bushing is internally threaded to match a thread on the breach F. The bushing Z is held to the breach holder K by the set screw L. The plate M fits into a T-slot in the holder K. This plate has a slot N cut in it so it will slip over the breach and prevent the breach from being pulled out when the same is pulled through the work. This plate comes in direct contact with the end of the bushing Z and it is obvious that this combination of threaded bushing, set screw and plate make a very strong construction for holding the breach while it is pulled through the work.

The holder K fits in a T-slot in the unit D. The screw P is used for adjusting the holder K so the broach may be brought in line with the work holding bushing E. The two screws Q are used to clamp the holder K so it will not move when correctly set. The pin R holds unit D to the end of the screw 0. The four lugs .S on unit D are a sliding fit over the rods J.

the nut B could be made to disengage with 20.

the screw C and be slid back. The means used for the return motion would therefore not affect the purpose of the attachment.

While it is preferred to employ the specific construction and arrangement of the parts shown and described, it will be understood that this construction and arrangement .is not essential to the broader features of the invention, and. may be varied or modified Within the scope of the appended claims as found desirable or best suited to the construction of the attachment or machine in which the invention is to be embodied.

I am aware that prior to my invention draw broaching has been done by using com plete machines, specially designed for this purpose. I therefore do not claim as my invention the principle of draw broaching broadly, but having explained the nature and object of the invention, and specifically described one form of mechanism in which it may be embodied, what I claim is 1. In an attachment of the class described, a revoluble nut; a driving bracket to co-act with said nut and consisting in part of means of attaching said bracket to a revoluble part of a machine of the class described; a base adapted to be detachably held to a machine of the class described; tool holder guides carried by a base; a tool holder slidable on said guides; a screw free to move longitudinally and attachable to said too]. holder; means to hold a. tool to said tool holder; means by which work operated on is retained in place.

2. In anattachment of the; class described, a revoluble nut, a screw, driving means coacting with said nut to operate said screw, said means being attachable to a revoluble part of a machine of the class described, and a tool holder operated by said screw.

3. In an attachment of the class described,

a tool holder, a screw attached to said tool holder, a nut, driving means to revolve said nut whereby sald screw is reciprocated longitudinally, guides for said tool holder, supports for said guides and a work plate in almement wlth sa1d tool holder.

FRANK H. MAYOH.

lVitnesses:

ROBERT THOMAS, L. J. MoNA-LLY.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.? 

